BERKELEY -- Just one game out of second place in the Pac-10, the Cal basketball team is the surprise team in the conference. Despite two transfers, a dismissal, a national team defection, a big man with a double-dose of plantar fasciitis, an untested point guard and a true freshman being depended upon as a go-to scorer, the Bears are 13-9 overall and 6-4 in the Pac-10. And they will take that record into a 5 PM clash with No. 21 Arizona at Haas Pavilion.

"I think defensively we're able to do a few more things," said junior power forward Harper Kamp, who, despite two knee surgeries prior to this season is leading Cal with a 14.3 scoring average. "We've struggled at times. In the beginning of the season, it looked like we were poised to be a really good defensive team, and we've had some slippage here and there. But, overall, I think, especially the young guys have learned how to play defense in the Pac-10, picking up on personnel stuff and match-ups and all the little things."

The Bears will have plenty on their hands Saturday night against the conference's second-leading scorer in Derrick Williams, who is netting 19.9 points per game.

"He was pretty good last year, and now he's stronger, he's shooting the ball from outside -- he doesn't shoot a lot, but he shoots a high percentage," said Cal head coach Mike Montgomery. "He's really explosive from the elbow area. He's not a center, really, but that's where he plays for them, so he gets matched up against the big players and he really has the ability to get angles to the basket and finish. He's one of the better players in the conference, clearly."

The last time the Bears squared off against the Wildcats (19-4, 8-2), Arizona squeaked by with a 73-71 win in Tucson, thanks in large part to a 16-of-22 free-throw night from Williams, who torched Cal for 31 points, 12 boards, a block and a steal in 34 minutes.

"Arizona, we hopefully have a chip on our shoulder as a team. We feel like we let one slip away," Kamp said. "He has a really quick first step and he's athletic, so when we were playing zone, it's hard to guard him in the high post. We're trying to figure out how to not foul him. He got so many calls down in Arizona. We've just got to figure out a way to play solid defense."

Williams leads the conference with a 63.4 shooting percentage, just ahead of the Bears' Markhuri Sanders-Frison (60.8 percent). He's also the Pac-10's most elite three-point shooter, making 24 of his 35 attempts from beyond the arc (68.6 percent).

"You've got to not let him get the ball," Kamp said. "You've just got to play as hard as you can every possession and try to minimize (touches). If he's going to jump and hit a three-pointer in your face and you're contesting it, there's not much you can do about that. Guys hit those shots sometimes and you've got to come down and play that much harder that possession."

In order to counter Williams, expect Montgomery to employ more zone defense, as he has in the past several games.

"We didn't play all; we played some (last time)," Montgomery said. "We got in foul trouble, obviously, with him getting 22 foul shots, so that wouldn't be the prudent thing to do to let him get exposed to one-on-one. It caused problems. The thing that we're going to have to do with Arizona is guard Williams. That's the key thing. They do a good job of getting the ball to him in space and he's hard to get square. Right now, people are creating contact and there's fouls called."

The Wildcats also feature the reigning Pac-10 Player of the Week in sophomore guard Lamont Jones, who led Arizona to two wins in the desert over USC and UCLA last week.

Jones hit 6-of-11 field goals and scored 17 points in the Wildcats' 85-74 win over the Bruins and recorded three assists and a career-high three steals in the 82-73 victory over the Trojans. Against USC, Jones also knocked down all six of his field goal attempts, including two from three-point land to finish with 17 points, three boards and two assists.

The zone will allow the Bears to save fouls against that deadly duo, a crucial factor given Cal's lack of depth.

"It's just difficult for us right now given the numbers of players that we have. We can't afford to really get in foul trouble," Montgomery said. "People have not shot many foul shots against us, so we're not as aggressive in zone as you would be in man. You don't expose yourself as much to foul trouble. I think it's a little more fatiguing in man, so we tried to protect ourselves and we try to work on man every day. We try to work on man, preparing for other teams, but if the zone works, we're likely to stay with it, but if not, we're likely to pay man."

Arizona will likely employ a man-to-man defensive game, something that the Bears have not seen much in recent weeks due to the variety of exotic defenses in the conference.

"We had a good game (against Arizona State), and the thing that's different a little bit is that you have all these crazy things, and it seems like you're preparing for something that's different every time," Montgomery said. "Oregon State is a 1-3-1, with Oregon it's the pressure and then you've got this match-up (with the Sun Devils). The one thing about it that you don't see as much (man) as you used to is that Arizona is pretty much going to pick you up and play you man, and at least then, you kind of can do - or try to do - what you work on most of the time. It seems like our preparation time is trying to show them how to do something different than what you normally want to do."

In the midst of a season-long four game winning streak, the Bears will be going for their fifth straight against the Wildcats to finish off a four-game home stand before moving on to face the Huskies and the Cougars up north in Washington.

"Getting this one (against Arizona State) was huge for us," Montgomery said after the Bears edged the Sun Devils 66-62 on Thursday. "There were some surprises around the league a little bit, and I think that what is becoming a little apparent to me after having gone through this thing in the first round is that the league is probably better than people want to give it credit for. It's actually pretty competitive across the board."

Arizona ranks second in the conference in scoring offense (77.2 points per game), third in scoring defense (65 points per game), first in free-throw percentage (74 percent), first in shooting (48.5 percent), first in three-point shooting (40.8 percent), first in three-point defense (26.5 shooting percentage), second in rebounding margin (+5.1) and second in three-point field goals (7.78 per game).